the executable installer of VMware Player 12.5.9, published in
January 2018, available from
<https://download3.vmware.com/software/player/file/VMware-player-12.5.9-
7535481.exe>,
is vulnerable.

JFTR: VMware Player 12.5.9 is the last version which runs on
32-bit Windows, and the last to support older CPUs.

Although running with administrative privileges (its embedded
application manifest specifies "requireAdministrator"),
VMware-player-12.5.9-7535481.exe extracts files UNPROTECTED
into subdirectories of the user's %TEMP% directory for later
execution.
An UNPRIVILEGED process/user running under the same user
account can tamper with these unprotected files between their
creation and their use, resulting in escalation of privilege.

For this well-known and well-documented vulnerability see
<https://cwe.mitre.org/data/definitions/377.html> and
<https://cwe.mitre.org/data/definitions/379.html> plus
<https://capec.mitre.org/data/definitions/27.html> and
<https://capec.mitre.org/data/definitions/29.html>

Demonstrations/proof of concepts:
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

The POCs work on standard installations of Windows, where the
user account created during Windows Setup is used.

This precondition is typically met: according to Microsoft's
own security intelligence reports, about 1/2 to 3/4 of the
about 600 million Windows installations which send telemetry
data have only ONE active user account.
See <https://www.microsoft.com/security/sir>

3. start the batch script created in step 1, then run the executable
installer: notice the error message from the Windows Installer,
and the start of the command processor with administrative rights!

B) "denial of service":
-----------------------

1. add the NTFS "access control list entry" (D;OIIO;WP;;;WD) meaning
"deny execution of files in this directory for everyone, inheritable
to files in all subdirectories" to the user's %TEMP% directory;

2. fetch the executable installer VMware-player-12.5.9-7535481.exe
and run it: admire the MISLEADING wrong error message
"The installer could not load a required DLL"!

2018-06-13 vendor acknowledged receipt:
"We will look into this and provide feedback in due course."

2018-06-14 vendor replies:
"It is my understanding that Workstation Player 12.x has
since reached end of general support (in February of 2018)
as per our Lifecycle Product Matrix
<https://www.vmware.com/content/dam/digitalmarketing/vmware/en/pdf/suppo
rt/product-lifecycle-matrix.pdf>."